Weight: 4 – 8cm diameter
New Zealand operates a mandatory shellfish quality assurance programme for all bivalve shellfish grown and harvested in areas for human consumption - shellfish caught outside this programme can only be sold for bait. The programme, managed by the NZ Food & Safety Authority in cooperation with the District Health Board Public Health Units and the shellfish industry, involves surveying water catchment area for pollution, sampling water and shellfish microbiologically over at least 12 months and biotoxin testing, among other measures.
There are eight species of surf clams in the QMS: ringed dosinia, silky dosinia, frilled venus shells, triangle shells, trough and large trough shells and two types of tutatua. The catch limits for surf clams off the south western coast of the North Island were substantially increased from 1 April 2013 following a biomass survey which established that there were substantial quantities of surf clams available off the Manawatu coast.